Data/internet not connecting on iPhone using Straight talk?

I just switched to Straight Talk Unlimited for my iPhone 4. Calls and messaging are working just fine, but my internet data (supposed to be included/supported) will never connect. Has anyone else experienced this? How did you get past this?

Larry H08.01.2013

You need to change some setting within the phone to get internet and picture messaging to work.
http://wiki.howardforums.com/index.php/Straight_Talk_iPhone
If you need more help go here and look at the "iPhone" sticky.
http://www.howardforums.com/forumdisplay.php/551-Straight-Talk